Nilton Di Chiacchio is Head of the Dermatologic Clinic, Hospital do Servidor Público Municipal de São Paulo, São Paulo, Brazil. Nilton Gioia Di Chiacchio is a dermatologist at Faculdade de Medicina do ABC, São André, and Hospital do Servidor Público Municipal de São Paulo, São Paulo, Brazil. Robertha Carvalho de Nakamura is a dermatologist at Instituto di Dermatologia, Santa Casa da Misericordia, Rio de Janeiro, Brazil. Michela Starace is a dermatologist at IRCCS Azienda Ospedaliero-Universitaria di Bologna and Assistant Professor at Alma Mater Studiorum, University of Bologna, Italy. Matilde Iorizzo is a dermatologist in private practice (Bellinzona and Lugano, Switzerland); she is also the vice President of the European Nail Society and the Secretary of the International Nail Society. Robert Baran is Head of the Nail Disease Center in Cannes, France; Baran and Dawber's Diseases of the Nails and their Management is now in its fifth edition.